dcb.StopBits = ONESTOPBIT;
dcb.XonChar = 0x13;
check(SetCommState(hComm, dcb), "SetCommState ");
COMMTIMEOUTS touts = new COMMTIMEOUTS();
check(SetCommTimeouts(hComm, touts), "SetCommTimeouts ");
check(!INVALID_HANDLE_VALUE.equals(hComm), "CreateFile " + COM);
String send = "Hello World";
int tlen = send.getBytes().length;